Final answer:
Bone is composed of collagen fibers and inorganic salts like calcium phosphate forming hydroxyapatite for strength, with collagen for flexibility. It contains four cell types - osteoblasts, osteocytes, osteogenic cells, and osteoclasts. Bone structure also includes compact and spongy bone tissues, as well as the periosteum and endosteum.
Step-by-step explanation:
The composition of bone, or osseous tissue, is a complex framework that includes several types of cells and materials. Bone tissue is predominantly made up of a matrix of collagen fibers and inorganic salt crystals. The primary components of the inorganic material are calcium phosphate and calcium carbonate, which combine to form hydroxyapatite. This crystalline structure incorporates other salts such as magnesium hydroxide, fluoride, and sulfate. The hydroxyapatite gives the bones their hardness and strength, while the collagen provides flexibility, preventing brittleness.
There are four main types of bone cells that play essential roles in bone function and development: osteoblasts, osteocytes, osteogenic cells, and osteoclasts. Osteoblasts are responsible for forming new bone tissue, osteocytes maintain bone tissue, osteogenic cells are precursor cells that differentiate into osteoblasts, and osteoclasts break down and resorb bone tissue. These cells work in harmony to repair, maintain, and remodel bone throughout an individual's life.
Besides cells, bone also includes specialized regions such as bone marrow, which is involved in blood cell production; the periosteum, a connective tissue layer that covers the bone; and the endosteum, which lines the internal surface of the bone. Compact bone tissue, found on the external layer of all bones, consists of osteons that give bones their smooth, strong, and dense appearance. In contrast, spongy bone tissue makes up the inner part of the bone and contains a network of trabeculae.